Process of making pistons



J. FLAMMANG.

PROCESS 0F MAKING PISTONS.

APPLICATION FILED M^Y23| I9I8. 1,344,875. Patented June 29, 1920.

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UNITED STATES JOHN FLAMMANG, F ST. LOUIS, MISSOURI, ASSIGNOR TVO OTTMARG. STAItK, OF ST.

PATENT oFFlcE.

LOUIS, MISSOURI. l

PROCESS 0F MAKING PVISTONS.

Specification of Letters Patent. Patented J une 29, 1920.

Application led May 23, 1918. Serial Nc.y 236,190.

T0 all whom t may concern.'

Be it known that I, JOHN FLAMMANG, a

citizen of the United States, residing at the city of St. Louis andState of Missouri, have invented a new anduseful Process of MakingPistons, of which the following is a specification.

This invention lrelates to the art of manufacturing pistons.

An object of the invention is to improve the art of manufacturingpistons whereby pistons may be produced that will impart uniformpressure against the cylinder wall all -around by the resiliency of themetal of which the pistons are composed, thus dispensing with thenecessity of using piston rings or packing in connection with thepistons.

Additional objects and various advantages will ,appear from thefollowingy description in which reference is made to the drawingsillustrating a piston in several stages of its construction inaccordance with the present invention, and in which- Figure 1 is a viewpartly in section, illustrating a form of casting from which the pistonis made.

Figs. 2 and 3 are views illustrating the casting after the upper portionthereof has been divided into segmental sections and the holes for thewrist pin have been formed.

Fig. 4 is a view illustrating the casting after it has been treated tocause the rev siliency of the metalto close the openings formed bycutting the upper portion of the piston body into segmental sections.

Fig. 5 is an elevation of the piston body after it has been subjected toadditional treatment.

Fig. 6 is' a view of the piston body having -thev wrist pin mountedtherein,jwhereby the within a cylinder.

The piston body is made from a casting including a lower ring 1, anupper ring 2,

connections 3 integrally uniting the lower and upper rings, and bossesty through which the holes for the wrist pin are formed.

By my present invention the upper ring 2 of the piston body is vdividedinto segmental sections, one of which is integrally united with each ofthe connections 3. The connections 3 also constitute supports for thefree ends of the `segmental sections so that both ends of each segmentalsection are firmly and rigidly supported. The segmental sections areformed by horizontal cuts 5 and inclined or oblique cuts 6 yextendingfrorn the ends of the cuts 5 to the upper edges of the` upper ring. Thisleaves `one end of each of the segmental sections integrally united withone of theconnections, and the opposite end of each segmental sectionoverlying a part of an adjacent connection 3. As shown the cuts 6 areoblique or inclined relative tothe axis of the piston, so that the endsof the segmental sections are overlapping. The piston body is thensubjected to treatment, preferably by heat, to change the moleculararrangement of the upper ring 2 so that the free ends of the segmentalsections will press upon theadj acent portions yof the connections 3 andthus close the cuts 5, as shown in Fig. 4. This treatment. may beeffected by mechanically ypressing the free ends of the segmentalsections to the positions desired and, while the piston toa dull redheat to change the molecular arrangement and set the material in thatshape. After that has been done the upper edge or endof the piston bodyis ground or finished to provide a properly smooth surface upon whichthe removable top or head plate of the piston may be mounted. y j

,'At a desired time relative to the above stages oftreatment, theholes-7 for the wrist pins are formed through the connections 3 and thebosses 4. As shown and as preferred, the holes 7 are inclined inwardlyand downwardly so that when the rwrist pin 8 is appliedv therein theconnections 3 will kbe sprung and the segmental sections of the upperring spaced apart. c

Either before or after the wrist pin is placed in the castingtheexterior surface of the piston body is finished to a sizein which thediameter of the lower ring 1 is slightly smaller than the diameterjofthe GTi cylinder for which the piston is intended, and in which theradii of the arcs of the connections 3 are also shorter than the radiiof the cylinder in which the piston is to be mounted. The upper ringcomprising the segmental sections above described is compressed to theposition which it will occupy when placed in the cylinder and; whileunder compression, is inished to the same diameter as the diameter ofthecylinder in which the piston is to operate. After being iinished thehead or top plate 9 is removably connected to the upper segmentalsections ofthe piston. The connection may be effected in any desiredmanner as by forming an interlocking tongue and groove connection lObetween the top plate and the upper portion of the piston, or by theemployment of locking keys ll engaging in slots in the upper ring of thepiston and in grooves in the top or head plate; or7 if preferred, bothof these connections may be employed as illustrated in Fig. 9.

The mounting of the wrist pin 8 in the inclined holes 7 retains theconnections 3 in their sprung shape permanently so that mechanicalpressure is applied to the connections 3 causing the full force of theresiliency thereoic to be exerted upon the segmental sections ot1 theupper ring.

Since the segmental sections of the upper ring have their endsapproximately in the same vertical plane with the lines of expandingforce, that is in approximately the same vertical plane with 'the axisof the wrist pin, it is clear that uniform or approximately uniformpressure will be exerted against the cylinder wall all around when thepiston is placed therein. As shown in Fig. 8 the diameter of the top orhead plate is the same as that of the cylinder in which the piston is tobe mounted, while the diameter of the upper portion of the piston bodywhen free from compression is slightly in excess of that of the headplate and also in excess of the diameter of the cylinder; although whenthe piston is mounted in the cylinder the upper portion of the piston iscompressed as shown in Fig. 9.

Preferably, the ends of the segmental sections of the upper portion ofthe piston interlock so that the free end of each section will be heldin annular alinement with the end of the adjacent section'which isintegral with the connection 3. 1

It is apparent that the order in which many of the various steps oftheprocess are formed is immaterial and may be varied without in the leastdeparting from the principle of the invention, as set forth in theappended claims.

What I desire to secure by Letters Patent, 1s:-

1. The process of making a ypiston which mental sections which overlapsaid connections; and treating the piston body to cause the segmentalsections to contact with said connections to close the spaces formed bysplitting the upper ring.

3. The process of making a pistonV which consists in forming a pistonbody of Va lowerring, an upper ring, and connections integrally unitingthe upper and lower rings; splitting the upper ring intosegmental.sections which overlap said connections; treating the piston body tocause the segmental sections to contact with said connections to closethe spaces formed by splitting the upper ring; drawing the segmentalsections of the upper ring toward each other to place the material undertension; and finishing the piston body to a size in which 'the upperring while compressed' under tension is of the same diameter as thediameter of the cylinder for which the piston is intended.

4. The process of making a piston which consists in forming a pistonbody of a lower ring, an upper ring, and connections integrally unitingthe upper and lower rings; splitting the upper ring into segmentalsections which overlap said connections; treating the piston body tocause the segmental sections to contact with said connections to closethe spaces formed by splitting the upper ring; drawing the segmentalsections of the upper ring toward each other to place the material undertension; and finishing the piston body to a size in which the upper ringwhile compressed under tension is of the same diameter as the diameterof the cylinder for which the piston is intended, and in which thediameter of the lower portion of the piston body is less than thediameter of the cylinder for which the piston is intended.

5. The process of making a piston which consists in forming a pistonbody of a lower ring, an upper ring, and connections integrally unitingthe lower and upper rings; splitting the upper ring into segmentalsections which overlap each other; treating the segmental y sections toclose the Vspaces formed by splitting the upper ring; drawing thesegmental sections of the upper ring toward each other to place thematerial under tension; finishing the piston to a size in which theupper ring while compressed under tension is of the same diameter as thediameter of the cylinder for which the piston is intended; andmechanically holding the upper portion of the piston body under tension.

6. The process of making a piston which consists in forming a pistonbody of a lower ring, an upper ring, and connections integrally unitingthe upper and lower rings; splitting the upper ring into overlappingsegmental sections which overlap the connections between the upper andlower rings; treating the upper portion of the piston to close thespaces between the segmental sections and the connections; drawing thesegmental sections of the upper ring toward each other to place thematerial under tension; finishing the piston to a size in which theupper ring while under tension is of the same diameter as the diameterof the cylinder for which the piston is intended; and mechanicallyholding said connections permanently under tension.

7. The process of making a piston which consists in forming a pistonbody of a lower ring, an upper ring, and connections integrally unitingthe upper and lower rings; splitting the upper ring into overlappingsegmental sections which overlap the connections between the upper andlower rings; treating the upper portion of the piston to close thespaces between the segmental sections and the connections; drawing thesegmental sections of the upper ring toward each other to place thematerial under tension; finishing the piston to a size in which theupper ring while under tension is of the same diameter as the diameterof the cylinder for which the piston is intended; and in which thediameter of the lower portion of the piston body is less than thediameter of the cylinder for which the piston is intended; and

mechanically holding said connections permanently under tension.

8. In the process of makin a piston, the steps of causing a portiono thepiston to press against the wall of the cylinder by the resiliency ofthe material of the piston, which comprises splitting the upper portionof the piston to form overlapping segmental sections; compressing theoverlapping segmental sections; and forming the overlapping sectionswith the same radius of curvature as the radius of curvature of thecylinder forV which the pistony is intended, while said sections arecompressed.

9. In the process of making a piston; the steps of causing a portion ofthe piston to press against the wall of the cylinder by the resiliencyof the material of the piston, which comprises splitting the upperportion of the piston to form overlapping segmental sections;compressing the overlapping segmental sections; forming the overlappingsections with the same` radius of curvature as the radius of curvatureof the cylinder for which the piston is intended, while said sectionsare compressed; and providing a top plate in connection with saidoverlapping sections.

10. In the process of making a piston, the steps of causing a portion ofthe pistonto press against the wall of the cylinder by the resiliency ofthe material of the piston, which comprises splitting the upper portionof the piston to form overlapping segmental sections; compressing theoverlapping segmental sections; forming the overlapping sections withthe same radius of curvature as the radius of curvature of the cylinderfor which the piston is intended, while said sections are compressed;and interlocking a top plate with said overlapping sections.

JOHN FLAMMANG.

